diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..9b788fa
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1784160687,
+        "narHash": "sha256-iYL/bixrb6FlHFu/gIuBYzq6c6lM5AAXsXNSWXtIgQc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4382ed2b7a6839d4280a9b386db49cbc5907414d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-26.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
index 83c6de2..584a088 100644
--- a/flake.nix
+++ b/flake.nix
@@ -67,7 +67,7 @@
             # `import openai_server` / `resource_plan` / `doctor` resolve.
             makeWrapper ${pythonEnv}/bin/python $out/bin/coli \
               --add-flags "$out/lib/colibri/coli" \
-              --set COLI_ENGINE "$out/lib/colibri/glm" \
+              --set-default COLI_ENGINE "$out/lib/colibri/glm" \
               --set PYTHONPATH "$out/lib/colibri:${pythonEnv}/${pkgs.python3.sitePackages}"
             runHook postInstall
           '';